Seal between relatively rotating parts



Jan. 26, 1965 H. A. LAND ETAL sEAE BETWEEN EELATIVELY EOTATING PARTS Filed May 2l. 1962 United States Patent O This invention has to do with a seal structure for bearings between relatively rotating parts to exclude foreign matter from the bearings and to preclude the escape of lubricant therefrom.

A general object of this invention is the provision of an improved seal structure capable of adjusting to axial, lateral, and tilting movement of relatively rotating parts between which the structure is installed. Because of its adaptation to these adjustments, a seal embodying the invention is particularly useful between relatively rotating parts of the crawler tractor track-guide rollers and the final drive shafts of a crawler tractor and the like, which parts lare subjected to severe irregular strains.

Another object of fthis invention is to provide a free-- floating seal structure ythat has the contacting seal faces of its rotor and stator element subjected to an equal pressure for the entire 360 about such elements.

Still another object of this invention is -to provide a close and intimate contact of the sealing Ifaces of the rotor and stator sealing elements.

It is still another object of this invention to provide a tubular pressure ring about one of two relatively rotating members for holding the sealing faces of the members in smooth and intimate contact with one another.

Still another object of this invention is to provide a face sealing structure for relatively rotating parts land compnising resilient deformable sealing means urgingly pressed against the back faces of the sealing rings of extremely hard sealing yfaces lapped to light band specioation wherein the resilient deformable sealing means apply equalized pressure along the entire extent of the sealing faces in i y order to provide a close and intimate seal.

t A more specific object in line with the above objective relative to face sealing structure, is the provision of such structure between the relatively rotating pants comprising, in combination with those parts, a free-floating pair of symmetrical seal ring parts of hard material having relatively rotatable, radially extending end surfaces which engage in the plane o-f the surfaces in face seal Contact with one another, land having concave backing faces; each of the yrelatively rotating parts having a concave face opposing a respective backing face of the seal ring parts and together presenting generally longitudinally acting, longitudinally opposing, concave pressure surfaces; and a pair ofsymmetrical, hollow, pressure O-rings of elastomeric material sealed between and compressed by rthe opposing concave pressure surfaces of said parts to float the pair of seal ring parts, said O-rings nesting in the conoave'backing faces and being compressed into an elliptical, hollow shape wherein, as viewed in cross section, the respective O-rings include major axes, which axes when extended intersecting approximately in the plane of saidseal-ring-part surfaces at a point radially outwardly of said surfaces, and which axes at `their intersection forming an acute, inwardly facing angle.

These and additional desirable objects inherent in and encompassed by the invention will be more readily comprehended after reading the following description with reference to the yannexed drawings consisting of FIG. ll which is a View illustrating a front elevational yview of a track roller and employed in a tractor of a crawler type;

FIG. 2 which is a sectional view taken transversely through a track frame of a crawler tractor :and actually 3,167,323 Patented Jan. 26, 1965 through an end portion of the track roller, and a bearing constructed according to the principles of this invention; and

FIG. 3 is an enlarged view of the sealing faces of the rigid sealing rings.

The present invention embodies certain improvements over the seal means disclosed in our copending application Serial No. 135,009, filed August 30, 1961. However, in describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended to be limited to specific terms so selected, and

it is to be understood that each Ispecific term includes.

all technical equivalents which operate in a similar manner to accomplish a similar purpose.

Turning now to the specific embodiment of the invention selected for illustration in the-drawings, the present bearing seal is particularly well suited for use in conjunction with a bearing for a roller which carries the track of a crawler-type tractor, the drawings illustrating a typical installation of a track roller. This roller unit which is designated 10 is one of several which are similarly mounted and distributed lengthwise and between laterally spaced track frame members 11 and 12. Each roller unit 10 has a roller 10a which is carried upon a nonrotatable shaft 13 which has its opposed ends anchored in main frame members 11 and 12. Bearing units or ybushings 14 land 15 are mounted on the inner periphery 15a of the track roller or rotor member 10a and bear against the track roller shaft or stator member 13. Each roller has a pair of circumferential grooves 16 for receiving and guiding the length of a track (not shown).

Identical seal structures are employed for the bearings 14 and-15 so it will sufice to refer solely to the seal structure illustrated in partial longitudinal section (FIG. 2) in conjunction with the bearing unit 15. One purpose of the bearing seal structure, which is generally designated 17, is to prevent the leakage of lubricating oil from the oil reservoir 18 in the shaft 13. If it were not for the seal structure, the lubricant within the area 18 would escape from the bushing 15 and the shaft 13. A Ifurther purpose of the structure Iis to prevent foreignmatter from reaching the bearing unit 15. g

The roller 10a at its end has an annular and radially and axially extending outer peripheral portion or flange 19 defining an annular recess 20 with the extension 21 of the shaft 13 in which is disposed the bearing seal structure 17. The roller 10a further has an outer facing radially extending wall portion 22 which is recessed to carry an O-ring 23. The wall portion 22 engages the face 24 of a `retainer plate 25 which is an annular flange encircling `the shaft extension 21, said flange being fastened against the face 22 by locking means 26 holding the O-ring 23 in place. The retainer plate 25 extends radially outwardly and has an inner boss portion 27 engaging thrust washer 28 about the shaft extension 21 and holds the thrust washer 28 against the radial side surfaces of the shaft 13 by the locking member 26. Attack roller shaft flange or bracket 3f) is spaced outwardly axially of the retainer plate 25 and comprises an elongated radially extending annular member about the shaft extension 21 and having radially extending hood 31 and axially extending hood 32, the hood members 31 and 32 acting as dust shields to minimize the amount of entran-ce of foreign particles yin the recess 20 into which the shield elements '31 and 32 are located. The retainer element-25 has a-hood projection 32a opposing the axially aligned hood member 32 for minimizing the entrance of `foreign particles into the recess 20. The lower half of a track roller shaft shaft extension 21 and also surrounds the lower half of louter axial end 34 of shaft l Y iskeyed by key structure 35,*frthe uppernalfof shaft por- Y' tion 34 being encompassed by track frame Ymerriberl 12V' which is locked by boltvtv to tle'brjacket extension 33,' the upwardV radialproje'gztiori3J.` 3fr the extensioni314' vacting somewhat as ka `guide 'against undueyhorizontatf shift of the roller unit'with respect tothe 'trackffrarnegVY n T lle-.retainer plate 25l1as anou'twfardly directed radi--A ally land diagonally extending faceSTthat is slightly" Y Y A with the hood portion 32a andv has a portionv of yits, "'pe-l y y concave `at :its ends, its' outward radial portion merging riphery engaging `w-ithan lelastomeric or resilientdeformtowhich shaft portion 314i andsealin'gvringv-rl, they compressed; loading is directedy axially to perrnit'tlsh eng'agementof-the sealing faces 42a andf44a and the relative rotation vnccu-rs between the sealyix'ig'fportionsvlza anllia.V The sealing faces 42 and 44 v fare of extremelyhard ,material, but Vas they. slowlyrvwear vfawayfdueto rotationaly frictional engagement of portions Y able pressure ring or tubular member 33 yof the .sealing unit 40, the member 38.having a tube 38a with anaper.-

ture 38b disposed in 4|the 'annular recess 20 between the, retainer plate and the track roller shaft. bracketA 30.7, A sealin'gring $9 of seal unit 40 is of extremely hard material Vand has radially and diagonally,extending inwardly directed surface or backing face 41 vengaging the other'side ofthe pressure'ring 38 of annular-extent and in general axial alignment .with the annular presst1re ring y 3S. The sealing ring 39` also has an'outwardlydirected l sealing face 42 -in a generally radial reference plane P1."

with Arespect to the axis'of! theY shaftY 13;. VThis sealing Y face isfextremely smoothaand'is ground Withinveryclosef Y' of surfaces `41 and45'of their respective sealing rings 39 tand 43.f"Radial'shiftingof the Vpressure rings 38iand 46 J areprevented byJ-trheirY conformationto their respective "backing faces .41',f45jof theirrespective'sealing rings 39, Lf43andtothe surfaces 37;49. l'

tolerances hav-ing a suggested surface smoothnessor liat'f` ground or lapped Vto light band:specification:V i'he-sealing tface 42 comprises .a sectionorpontion 42- thatmay lbe ground to two light bandspeciiications and fa portion 42h that'may-be `grc` undqtofive light band specif'cationsw;

the surface 42b` being at a slight inward annular tapered relation .vithres'pect to the portion 42g. g f Y A complemental sealing vring 43,'of thefseal 'unit 4? isv somewhat identical to but amirrorimage of thefsealingy g vring 39and comprises an: annular elementabout'fthe shaft@y extension V21.Y lTljuering 43 has "a radially extendingin` wardly directedsurfacer or sealing face 44 ofA lightband I' specicationsfor complemental engagement with -the Y come ink rconta'ctrwith one another. yThe sealrings 39 and llljmay befnradeof such'material as Stellitei which may becomposed generallyflof 4the following constituents (expressed inlpercent by weighty. 4

Y 'Y A Percent, approx.

It win'I be inbred that', the. aanmaning against the pressure rings 38, 46 extends about the annular periphery i jbore or chambers 38b.andu46b either under atmospheric r pressure or they-caribe pre-pressurizedprior to lnstallaa ytion beyond atmospheric pressure todnsure'tighttting rengagementwith'the sealingrings 39 and 143 when 1n-v stalled 1in andv compressed :by ithe, roller unit 10 tov developV aV closer and more facesr42f'z, 4441? f lintimate''contact forv the sealing 'lfhusfisY ca beseenY by the applicants sealing arrangement'employinfg'a pair of tubular pressed rings`,' equalized! pressure maybe applied about theentire annular extentof sealing -face 42and similarly has a flat portion '44a groundl f, l'

Vor lapped llatto within a suggested two light bandV specirings y39 and y4Z have inwardly" radially project-inging portions, 46 and '47T respectfully-delining' a-groov'elS' 1 therebetween., yThe sealing ring'"43 has abacking surface 45 assimilatinglthe bacldng'surface 41Vof the-sealing ringl l`39fand ycradlesl a resilient, orsdeformable Vtubular ring 4j6 having an annular prtionr46af 'and anaperture 46bg-fthe r pressure ring 46 being'identicalto;v the pressure ring 38.

The pressure ring 46jon its outwardly'directed'sidefengages'the'r'adially diagonally 'extendingiconcave inwardly,j Vll the surface-Mat yits inwardlydirectedv endvforminga hoff tion of thehood member'xz Qand'IaSsmilatng'the con-rfi p Vfiguration ofthe, outwardly directed concave surface; '37 of1theretainer" plate 25;. Anja'dditional sealingring'SiBj surrounds'theou'tward' end ofgtheshaft 'portion 2l snugly f between the shaftqportionlfand the;v inner periphery porSQ tionY SL/ofl Ythefbr'ae'ket- Sil topreyenteritrance of Lforeign er a 'highs compressed AO" cation; w The tlat-`portions 42a yanjdf44a1press in hush/. contact with 'one yanother with'their interface of engager' f ment in the reference plane P;. vThe ring 43 has aradially f extending outwardly divergingportion 44h and forms with portion V421g ya V-shape opening45a. '.Bothfof theusealingjf the 'backing-faces, 41,1545 ofvthehsealing ringsf39,v 43 .to insure Y'equal and nat and ilushfengagement of the sealing surfaces or faces 42a, 44a and thereforeinsure against any vleakageV of oilforffoi'eignparticles pastffthe'seal'junit 40; Also the applicants device', thrfough distortion of the rub;

ber I rings I 38Y and, 46 by 'axial l fJading,--V permits the seal.

-' unitl40tofocct1py-'a smallenconned space,wl1,ich'isa desirable feature of this track rollerunit 10: and yet permitsa 'minimum of axialfdisplacement@offthe shaft 13` 'l Vwith respect vtoV the roller element 10a;

VBy careful `formatin or production of the' contour r*of*l f y theibacking'rfac'es 41,':45 the spring actionof pressure ringsrfSS and 46 maybe controlled. InV this respect it` will` face extent-'disposed' generally radially of thefaxis of the shaft 13 and that the application of force istherefor'e in a longitudinal direction f generallyperpendicularV to` the radial surface to compress the'pressure vrings:378112'1nd 46. Thecombination "of-'a pai'rjoffftubular pressureringsv permits'more latitude'ffor sidefmovementand allowsv more resiliency between and latera 'displacement of the shaft 13 with:respecttotherrollerflllzirandfthe'pressure applied u to vthe sealing Yfaees4241,44d is*more'constant'rand more equal. 1 Furthermore; since'the pressure'rings 38;1461-are `identical to one fanotheriand the` sealingrngs139, 4.3 are m'irrorl imagesof foney another tner'ev'r'naybeV interchange` fabilitybetween the pressure rings an'dbetween the sealing Y gfri1'ss.. Y It, is imprtsritt@ "Lapplrrresurs-f evenlrdirsstly jinil line withfthersealing faces allftheway around the shaft l j's'ofas'to not'rdistorrt rth'esealirig faces'an'd thiswfis'rbe'stac-y he pressure rings`38 and 46Ymayhave their annular l Vseal;'structurey i inyo'therf: co tructijan besides i been herein shown and described with view of illustrating the principles of and the method of practicing the invention.

What is claimed is:

1. Face sealing structure between rotor and stator parts comprising, in combination with said parts:

` a free-oating pair of symmetrical seal ring parts of hard material having relatively rotatable, radially extending end surfaces which engage in the plane of the surfaces in face seal contact with one another, and having concave backing faces;

each of said rotor and stator parts having a concave face opposing a respective backing face and together presenting generally longitudinally acting, longitudinally opposing, concave pressure surfaces; and

a pair of symmetrical, hollow, pressure Oarings of elastomeric material sealed between and compressed by the opposing concave pressure surfaces of said parts to float the pair of seal ring parts, said O-rings nesting in the concave backing faces and being compressed into an elliptical, hollow shape wherein, as viewed in cross section, the respective O-rings include major axes, which axes when extended intersecting approximately in the plane of said seal-ringpart surfaces at a point radially outwardly of said surfaces, and which axes at their intersection forming an acute, inwardly facing angle.

2. The invention of claim 1, wherein said O-rings are of a normal circular cross section and have the hollow interior thereof each one pre-pressurized to a superatmospheric pressure similar to the pressure of the other, whereby to balance the opposed sealing forces on the floating ring parts.

3. Face-sealing structure between a shaft and a housing, said housing being axially recessed at an end adjacent a portion of said shaft, and said shaft portion extending through and beyond the corresponding end of the housing, said structure comprising:

a free-floating pair of symmetrical seal rings having relatively rotatable, radially extending end surfaces which engage in the plane of the surfaces in face seal contact with one another, and having con- Cave backing faces;

a rotor flange fitting against a surface of the recess of said housing;

a stator ange drivingly connected to said shaft, each of said rotor and stator flanges having a concave face opposing a respective backing face and together presenting generally longitudinally acting, longitudinally opposing, concave pressure surfaces;

a pair of symmetrical, hollow, pressure O-rings of elastomeric material sealed between and compressed by the opposing concave pressure surfaces of the anges and seal rings to float the pair of seal rings, said O-rings nesting in the concave backing faces and being compressed into an elliptical, hollow shape wherein, as viewed in cross section, the respective O- rings include major axes, which axes when extended intersecting approximately in the plane of said sealring-part surfaces at a point radially outwardly of said surfaces, and which axes at their intersection forming an acute inwardly facing angle;

a stator seal between the stator flange and said shaft;

and

a rotor seal between `the rotor flange and said housing.

4. The invention of claim 3, said structure further comprising axial hood projections carried by the respective flanges in closely spaced apart confronting relation; and a `hood member carried by the stator flange and extending radially outwardly from a point proximate to the adjacent axial hood projection, said rotor and stator seals and said hood projections cooperating with the seal rings and 0-rings to block foreign matter.

References Cited in the file of this patent UNITED STATES PATENTS 2,989,966 Marshall June 27, 1961 3,073,657 Oxford Jan. 15, 1963 3,086,782 Peickii et al Apr. 23, 1963 FOREIGN PATENTS 265,615 Switzerland Sept. 16, 1950 1,255,283 France Jan. 23, 1961 1,101,071 Germany Mar. 2, 1961 

1. FACE SEALING STRUCTURE BETWEEN ROTOR AND STATOR PARTS COMPRISING, IN COMBINATION WITH SAID PARTS: A FREE-FLOATING PAIR OF SYMMETRICAL SEAL RING PARTS OF HARD MATERIAL HAVING RELATIVELY ROTATABLE, RADIALLY EXTENDING END SURFACES WHICH ENGAGE IN THE PLANE OF THE SURFACES IN FACE SEAL CONTACT WITH ONE ANOTHER, AND HAVING CONCAVE BACKING FACES; EACH OF SAID ROTOR AND STATOR PARTS HAVING A CONCAVE FACE OPPOSING A RESPECTIVE BACKING FACE AND TOGETHER PRESENTING GENERALLY LONGITUDINAL ACTING, LONGITUDINALLY OPPOSING, CONCAVE PRESSURE SURFACES; AND A PAIR OF SYMMETRICAL, HOLLOW, PRESSURE O-RINGS OF ELASTOMERIC MATERIAL SEALED BETWEEN AND COMPRESSED BY THE OPPOSING CONCAVE PRESSURE SURFACES OF SAID PARTS TO FLOAT THE PAIR OF SEAL RING PARTS, SAID O-RINGS NESTING IN THE CONCAVE BACKING FACES AND BEING COMPRESSED INTO AN ELLIPTICAL, HOLLOW SHAPE WHEREIN, AS 